anatomy joints/ligaments/movements

3 types of joints by movement

synarthrotic, diarthrotic, amphiarthrosis

synarthrotic

immovable joints -fibrous connective tissue

diarthrotic

movable joints - synovial fluid provides lubrication

amphiarthrosis

slightly moveable joints - cartilaginous connective tissue

all synovial joints are

diathrotic

most (not all) amphiarthrosis joints are

cartilaginous

most (not all) synarthrosis joints are

fibrous

fibrous joints

3

articular surfaces of two bones are connected by dense fibrous connective tissue (ex sutures)

cartilaginous joints

hyaline or fibrocartilage connects bones, slight movement

synovial

most of the body’s articulations, free movement diarthrosis)

3 types of fibrous joints

syndesmosis, suture, gomphosis

syndesmosis

fibrous joint

cord of fibrous tissue

amphiarthrosis - have a “give” but no true movement. (exception because other fibrous joints are synarthrotic)

ex. is distal tibiofibular joint between the tibia and fibula

-have high ankle sprains

-are also between spinous processes of vertebrae and between diaphysis of radius/ulna

suture

-fibrous joint

-short fibrous CT fibers (skull only)

-synthroses

gomphosis

-fibrous joint

-tooth within its alveolar fossa

-short periodontal ligament

-cony shaped bony process in a socket

-synarthrosis

2 types of cartilaginous joints

synchondrosis and symphysis

synchondrosis

-cartilaginous joint

a plate of hyaline cartilage unites bones

sites of growth during youth

ex. joint between manubrium and first rib, epiphyseal plate

-synarthrosis

symphysis

-cartilaginous joint

pad or plate of fibrocartilage

ex. joint between bodies of adjacent vertebrae, pubic symphysis)

-amphiarthrotic

6 types of synovial joints

gliding, hinge, ball-n-socket, condyloid, pivot, saddle

gliding

-synovial joint

smooth articular cartilage that allows bone to slide

found in intervertebral discs, carpals and tarsals

-diarthrotic

hinge

-synovial joint

permit flexion and extension only (only go up and back)

found in elbows, knees, fingers, toes

-diarthrotic

pivot

-synovial joint

allows rotation

ex. ulnar notch and radial notch, first intervertebral joint C1 atlas and C2 fit together allowing for rotation of saying “no” (atlantoaxial joint)

-diarthrotic

saddle joint

-synovial joint

-allows opposition

-fits like a rider in a saddle

ex. first carpometacarpal joint for thumb, sternoclavicular joint

diarthrotic

ball-n-socket

-synovial joint

-most freely moveable joint

-femur and humerus

ex. coxofemoral, glenohumeral

-diarthrotic

condyloid

-synovial joint

-freely moveable, not as freely moveable as ball-n-socket

-allows for flexion, extension, abduction, adduction, circumduction, NOT rotation

-key locations are wrist, fingers, toes

-diarthrotic

saddle vs. condyloid - how to tell diff

condyloid joints have a convex surface sitting on a concave surface (rounded on cup like surface)

its saddle joint if it looks like legs sitting on a saddle

saddle joints also allow opposition (thumbs touching fingers) while condyloid joints do not

type of joint movements - origin

part of muscle attached to the immovable bone

type of joints movements - insertion

• part of the muscle attached to the movable bone

When a muscle contracts across a joint, its insertion is pulled..

toward its origin

3 types of movement -

gliding, angular, special

gliding movement

flat bones glide over one another

-also found in cartilaginous joint movement

angular movement

changes in angle (synovial joints)

special movement

those at specific joints

flexion/extension

dorsi/plantar flexion

supnation/pronation

elevation/depression

protraction/retraction

eversion/inversion

knee is made up of what three joints

condyloid, gliding, and hinge

knee characterstics-

knee is the largest, most complex joint

-functions as Hinge even tho 3 joints work together

-medial condyles of femur and tibia make condyloid joints

lateral condyles of femur and tibia make another condyloid joint

-patellar surface of femur and patella make gliding joint

-flexion and extension makes Hinge joint

extracapsular and intracapsular ligaments

extracapsular are outside joint capsule, intracapsular are inside joint capsule

menisci

separates tibia and femur

eversion sprains are much rarer than inversion sprains. why?

the greater inversion ROM (range of motion) opens the ankle up to more likely injury than lateral ROM

bursae

a small, fluid-filled sac that acts as a cushion or shock absorber between moving parts in your body, like bones, muscles, tendons, and skin, reducing friction for smooth movement around joints such as the shoulders, elbows, hips, and knees

ankle joint complex is made of

talocrucal, talocalcaneal. transverse tarsal. the anke holds 10x body weight

which two ankle joints tear easily

the calcaneofibular and anterior talofibular ligament tear easily. most sprained ankle injuries occur here.

elevating a joint allows

blood to flow

lisfranc joint

where metatarsals meet tarsals

Life-Span Changes

• Fontanels of skull harden in first 2 years

• Epiphyseal plates harden from ages 14-20 years.

• Fibrocartilage loses water, decreasing flexibility of intervertebral joints and knees

Life-Span Changes

• Collagen changes causing stiffening beginning at age 30.

• Joint stiffness is an early sign of aging

• Fibrous joints first to change; can strengthen over a lifetime

• Changes in symphysis joints of vertebral column diminish flexibility and decrease height 

Life-Span Changes

• Synovial joints lose elasticity

• Disuse hampers the blood supply

• Activity and exercise can keep joints functional longer, lessens stiffening

• Sprains

• damage to cartilage, ligaments, or tendons associated with joints

• forceful twisting of joint

Bursitis

• inflammation of a bursa

• overuse of a joint

Arthritis

• inflamed, swollen, painful joints

• Rheumatoid Arthritis

• Osteoarthritis